Fluid-pressure motor



April 5,1926.

E. H. SHAFF FLUID PRESSURE MOTOR Sheets-Sheet 1 Filed April 2, 1925 Kwamen 'o 2 Aprn 6,1926.

E. H. SHAFF FLUID PRESSURE MOTOR l v Filed April 2, 1925 2 sheets-sheet 2 &

mm ham,

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Patented pr. 6, 1926.

Unirse stares PATENT osrics.

ERNEST E. SHAIEF, OF GRAND HAVEN, MICHIGAN, ASSIGNOR TO WILLIAM I-I. KELLER INC., OF GRAND HAVEN, MICHIGAN, A CORPORATION OF MICHIGAN. i

FLUID-PRESSURE MOTOR.

Application filed April a,

To all whom it may conce/rn Be it known that I, ERNEST H. SHAFF, a citizen of the United States, and a resident of Grand Haven, county of Ottawa, State of Michigan, have invented an Improvement in F luid-Pressure Motors, of which the following description, in connection with the accompanying' drawings, is a specification, like characters on the drawings representing like parts.

My invention relates to fluid pressure motors, and particularly but not exclusively to that type of impact tool known as a pneumatic hammer.

My invention will be best understood from the following description when read in the light of the accompanying drawings of an example of my invention selected for illustrative purposes, while the scope of my invention will be more particularly pointed out in the appended claims.

In the drawings Fig. 1 shows an elevation of a pneumatic hammer constructed according to my invention and with parts in section;

Figs. 2 and 3 are longitudinal sections of the pneumatic hammer according to Fig. l and showing the valve in dierent positions. In Figs. 2 and 3 for convenience of illustration the ports and passages as far as possible are moved into the same plane, the true position and number of ports and passages being indicated by Fig. 4 which is a section of the pneumatic hammer on the line 4 4 of Fig. 3.

Referring to the drawings and to the preferred embodiment of my invention I have shown a pneumatic hammer having a barrel 1 in the bore 3 of which reciprocates the hammer piston 5, the latter being ar 1923. Serial No. 629,263.

receives the forward valve cage section 15 and the rearward valve cage section 17, the valve cage so formed having a bore which forms a prolongation of the bore 3 and receives the tubular valve 19 which interiorly is of such diameter that the hammer piston can enter it. f

For supporting the tool I herein provide a grasping handle 21 which has integrally formed therewith the sleeve 23, the latter being interiorly screw threaded and received nipple 27 on the grasping handle. Formed through the grasping handle is a passage 29 which, as will be understood, is placed in communication with the nipple 27 and leads to a chamber 31 in the base 25 of the grasping handle. Y

As illustrated, for admitting airvto the rearward end of the bore 3, the chamber 31 in the base of the grasping handle has in communication therewith a plurality of passages 33 which extend through the valve cage section 17 and are connected by radial.

passages 35 with the interior bore of said section said radial passages opening into said bore through ports positioned to be opened and closed by the valve 19.

For exhausting the rearward end of the bore 3 in the present embodiment of my invention the forward end of the valve controls a series of radial passages 37, each of which is in communication with a corresponding passage 39 leading through the walls of the lbarrel and valve cage section 15 to the atmosphere from an annular groove 41 formed in the enlargement 45 of the bore of said valve cage section. v

`The enlargement 45 of the bore -of the valve cage section 15 aligned and communieates with the smaller enlargement 47 of the bore of the' valve cage section 17, and leading from the groove ab at the rearmost end of the enlargement Ll5 is a passage 49 formed in the walls of the valve cage section l5 and the cylinder and opening into the bore 3 adjacent the rearward end of the shank of the rivet set. Leading from one of the passages 33 to the enlargement l-T is a somewhat restricted passage 51. Herein for alternately connecting the passage ett) to the passages 3S) and 5l so as to admit and exhaust air to and from the front end of the bore 3 and for purposes hereinafter set. forth the forward portion of the valve is provided with the annular exterior llanges 53 and which lit the enlargement l-, while the rearward portion of the valve is provided with a pair of annular flanges 5T and 59 which lit the enlargement 4:7.

The operation of the device so far described is as follows. lVith the parts in the position shown b v Fig. 2 motive fluid passes from the passage Q9 into the chamber 8l and hence to the rearward end of the bore 3 bv wauwT of the passages 325 and 35, the latter in this position of parts being uncovered by the rearward end of the valve. This causes the piston to travel forwardly, the air in front of the piston exhausting through the passage 49 to the atmosphere b v wav oll the chamber 61 between the valve flanges and 57 and the passages 39. lVhen the piston reaches the front end of the bore il the valve by means hereinafter to be described shifts to the position shown bv Fig. 3 which causes the rearward en-d of the valve to close the ports 35 and e-onsequentlv stop the admission to the rearward end of the bore 3. It also interrupts the communication between the passages 39 and l?) and places the passage 11.79 in communication with the passage 5l, and at the same time the front end of the valve uncovers the ports 37. This admits motive fluid to the front en-d of the c vlinder bv wa v of the passage Q9. the chamber 3l. the passage 33 shown at the bottom of Fig. 3. the passage 5l, the chamber 6l and the passage 49. and in consequence the hammer moves rearwardly. the air at the rearward side ol the hammer passing to the atmosphere by vav of the passages 37 and 39.

For shifting the valve rearwardl't1 l herein provide the wall of the barrel with one or more passages G3 which open into the bore 3 through a port or ports (i5 positioned to be uncovered bv the rearward end of the hammer when the same travels forwardly. the passage or passages 63 communicating with the chamber 67 in front of the valve flange b v wav of a somewhat restricted passage 6G. `When the forwardly traveling hammer uncovers the port or ports G5 air is admitted from the bore 3 to the chamber 67 and this air acting on the forward side of the flange 53 overcomes the pressure of the air in the chamber (56 acting upon the rearward side oi the llange 5S) and in consequence rearward movement of the valve is initiated. As shown in Fig. 3 I form in the walls ol,l the valve cage sections a passage (it) of relatively large volume which passage is supplied with air b v a restricted passage il in communication 'with one of the ports Leading from the passage GS) to the chamber o? is a narrow Slot T3 which is positioned lo he, closed bv the llnngc {il} when the valve is in its 'orward position and to be uncovcrial b v said llange when the valve is in its rearward position. In consequence when rearward motion o' the valve is initiated by air passing through the port or ports (35 and passagcsl andlti to the chamber 67 the flange 53 uncovers the slot 'T3 to admit additional air to the chainber G7. It will be noted. that when the piston is in the position shown in Figs. 2 and 3 and the valve shifts from the position shown in Fig. 2 to the position shown in Fig. 3 the chamber G7 will be vented to the atmosphere by wa)v of the passage {Si} and the bore 3 because the front end of the valve then uncovers the passages Il? which eonneet the bore 3 to the atmosphere. The air admitted to the chamber (3T through the slot i?) is elliective to maintain enough pressure in the chamber ($7 after the pa... il? are opened to exert considerable loree l'or holding the valve in its rearward position. ,\s the piston moves rearwardl'v the pressure in the chamber (3T increases nvnnentarilv dnring the transit of. the piston over the port 65, and when the front end of the piston again uncovers the port G5 the pressure in the chamber 67 drops slightly.' owing Ato the somewhat low pressure conditions in the front of the bore 3 existing at; this time bjv reason o'" wire drawing through the passage 51.

In Fig. 2 l have shown in communieation with the chamber (3S behind the valve flange 59 a radial passage TT whirh connects with the rearward end of a passage T5). the passage 79 being placed in eoninuinieation with one of the passages fl?, b v a passage Sl of .smaller diameter than said passage Tft. 'lhe passage T9 opens into the end o l: (he i'iassage ffii. and the latter into the end ol' the passage S5. the passages T9. S9 and S5 in the order enumerated being of proe'ressivelv iin-reasing diameter. The pass ge opens into the bore 3 in the valve (faire seetioii l5 lust forwardlyv of the front end of' the valve lil. lVhen the valve is in its rearwzwd position as indicated bv Fig. fl the air whieh passes through the iassage Sl exhausts lo the almosphere bv wav of the passages Tt). .Q23 and 85. the bore 2. and the` passages 3T and $10. The arrangement of passages just deserihed lill) lli forms anl ejector, the air passing through the passage 81 entering the passage 7 9 in the form of a jet which creates suction in the passage 77 and chamber 68, and the reduced pressure caused by this suction in conjunction with the pressure in the chamber 67 acts to hold the valve in its rearward position againstthe effect of the pressure in the chamber 61. Y

In the present construction when the piston travels rearwardly it interrupts communication between the passage 85 and the bore 3. rlhis will effect forward movement of the valve, for when this occurs air cannot escape from the passage 85 to the atmosphere, and consequently the ejector effect above described is destroyed, pressure then building up in the chamber 68 because the passage 8l is still connected to the live air supply. The building up of pressure in the chamber 68 under these conditions exerts enough force aided by the pressure in the chamber 61 to overcome the pressure in the chamber 67, and in consequence the valve moves forward, which relieves the chamber 67 of pressure because the forward movement of th-e valve closes the slot 73 and connects the port 65 to the atmosphere by way of the bore of the cylinder, 'passage 49, chamber 61 and passages 39.

Although l have described for purposes of illustration one specific embodiment of my invention it is to be understood that I am not limited thereto, but that within Ythe scope of my invention wide deviations may be made therefrom without departing from the spirit of my invention.

Claims.

l. A pneumatic hammer having in combination Va cylinder, Aa hammer piston, a valve; means providing an ejector having a nozzle, a suction orifice and a combining tube; sai-d nozzle being permanently open to the source of motive fluid supply to the machine, said suction orifice permanently communicating with a rearwardly facing pressure surface of said valve, said combining tube opening into said cylinder, an exhaust passage for one end of' said cylinder, and said piston intermittently interrupting the communication between said combining tube and cylinder.

2. A pneumatic hammer having in combination a cylinder, a hammer piston, a valve for controlling said hammer having a working pressure surface, and means including fluid conduits controlled by said hammer piston for alternately subjecting said working pressure surface to positive fluid pressure and to suction.

3. A pneumatic hammer having in combination a cylinder, a hammer piston, a valve for controlling said hammer piston, said valve having a working pressure surtace, and means including fluid conduits for alternately subjecting said working pressure surface to positive fluid pressure andfto suction.

.4. A pneumatic hammer having in combination a plurality of movable members one of which serves as a hammer piston and another as a valve, said valve controlling said hammer piston and having a pressure surface, and means including fluid conduits controlled by the movement of one of said members for alternately subjecting said pressure surface topositive pressure and to suction.

5. A pneumatic hammer having in combination a cylinder, a hammer, a valve, means providing an ejector having a discharge conduit communicating with the atmosphere by way of the hammer chamber of sai-d cylinder, means for intermittently interrupting suoli communication, and said valve having a working pressure surface acted upon by gaseous fluid the degree'of pressure of which is controlled by said ejector.

6. pneumatic hammer having in com-` bination a cylinder, a hammer, a valve,-

means providing an ejector cooperating with said` valve, and means for alternately open-v ing and closing the discharge conduit of said ejector.

7 A pneumatic hammer having in combination a cylinder, a hammer, a valve having a working pressure surface, means providing an ejector discharging into said cylinder and arranged for creating suction on said working pressure surface, an exhaust passage for said cylinder controlled by said valve, and said hammer controlling lthe discharge of said ejector into said cylinder.

8. A pneumatic vhammer having in combination a cylinder, a hammer, a valve for controlling said hammer, an exhaust port for said cylinder' controlled by said valve,means controlled by said hammer' for shifting said valve for opening said exhaust port, an ejector discharging into the atmosphere by way of said cylinder and said exhaust port, said ejector' creating suction for holding said valve after it is shifted, and said hammer interrupting the discharge of said-ejector when said valve is again to be shifted.

9. A pneumatic hammer having in combination a cylinder, a hammer, a valve, said valve having avworlring pressure surface effective to move the valve in one direction and a working pressure surface of different area effective to move the valve in an opposite direction, meansv for admitting motive fluid to said first surface, means providing an ejector for creating suction on said second mentioned area, and means for interrupting the discharge from said ejector for causing the building up of pressure on said second mentioned area.

10. A pneumatic hammer having in combination a cylinder, a hammer, a valve, said valve having a working pressure surface etfective to move the valve in one direction and a Working pressure surface of ditl'erent area efl'ective to move the valve in an opposite direction, means controlled by said hammer for intermittently admitting motive liuid to said lirst surface, means providing an ejector for creating suction on said second mentioned area, and means :tor interrupting the discharge from said ejector tor causing the building up of pressure on said second mentioned area.

ll. A pneumatic hammer having in combination a cylinder, a hammer, a valve, said valve having a working pressure surl'ace etitective to move the valve in one direction and a working pressure surt'ace o't' diti'crent area ellective to move the valve in an opposite direction, a port positioned to be overrun by said piston for causing pressure lluid to act on said tirst mentioned surrace tor shifting said valve, and means providing an ejector tor creating suction on said second mentioned surface, and said ejector discharging into said cylinder.

12. A pneumatic hammer having in com bination a cylinder, a hammer. a valve, said valve having a Working pressure surface eliective to move the valve in one direction and a working pressure surface olf diti'erent area ell'ectivc to move the valve in an opposite direction, an exhaust passage controlled by said valve, a port positioned to be overrun by said halmner tor causing' actuating Huid to flow from said cylinder and act on said lirst mentioned surface whereby to cause said valve to shift and open said exhaust passage, and means providing an ejector discharging into said cylinder for creating suction on said second mentioned surface of said valve when said exhaust passage is open,

13. A pneumatic hammer having in combination a cylinder, a hammer, a valve, said valve having a uf'orling pressure surface etfcctive to move the valve in one direction and a working pressure surface of ditierent area etltective to move the valve in an opposite direction, an exhaust passage controlled by said valve, a porti positioned to be overrun by said hammer for causing actuating` lluid to How from said cylinder and act on said lirst mentioned sui-tace whereby to cause said valve to shift and open said exhaust passage, means providing an ejector discharging into said cylinder for creating suction on said second mentioned surface ot said valve when said exhaust passage is open, and said ejector being supplied with motive fluid 'tor subjecting said second mentioned sur'lace to positive pressure when said exhaust passage is closed,

le. A pneumatic hammer' having in combination a cylinder, a hammer, a valve, said valve having a vvorliing pressure surl'aee eti'ective to move the valve in one direction and a working pressure surface oi dilierent area eiiective to move the valve in an opposite direction, an exhaust passage controlled by said valve, a port positioned to be overrun by said hammer lor causing actuat ing l'luid to tion' 'l'rom said cylimlcr and act on said tirst mentioned surtace i'or causing said valve to shit't and open said exhaust passage, means I novidiug an ejector cooperating with said second mentioned surface, and said ejector being constantly supplied with motivel i'iuid aiul discharging into said c vlinder through a port overrun by said hammer, \\.'hereb v said ejector is etleetive lo subject said second mentioned surt'ace ol said valve to suction in one position of said valve and said surtace is sub] lcted to positive pressure when the discharge of said c iector interrupted.

lo. In a pneumatic hammer. having in combination a cylinder, a hammer, a valve, said valve having u'orhing pressure surfaces clliective to move the valve in opposite directions, a port overrun by said hammer for conducting actuating' tluid from said cylinder 'tior acting on one ot said pressure surfaces and initiating movement of said valve in one direction, said port being in constant communication vvith the space adjacent said surface, means responsive to the movement so initiated for admitting live actuating tluid tor acting on said area, and means l'or subjecting another area to suction upon completion of said movement of said 'alve.

lo. In a pneumatic hammer having in combination a cylinder, a hammer, a valve. said valve having ivorlting pressure surfaces effective to move the valve in opposite directions, a port overrun by said hammer 'lor conducting actuating tluid trom .said cylinder for acting on one of said pressure surifaces and initiating movement' of said valve in one direction, said port being in constant communcatiou with the space adjacent said surta e, means responsive to the movement. so initiated for admitting live actuating fluid for acting on said area,` means t'or subjecting another area to suction upon completion ot said movement o'l said 'alve. and means controlled by said hammer for converting said suction to positive pressure t'or moving said valve in thc opposite direction.

17. A pneumatic hammer having in combination a cylinder, a hammer, a valve. said val having Working pressure surfaces etlzective to move the valve in opposite directions, conduit means constantly supplied with live motive liuid t'or admitting live motive i'iuid to one of said pressure surfaces when said valve is moved in one direction, a port overrun b v said haimner for conductingl actuating tluid Vlrom said cylinder vlor so moving said valve, and means for subjecting titl another pressurearea 'to suction after completion of movement of said valve.v

18. A pneumatic hammer having in combinationV a cylinder', a hammer, a valve, said valve having working pressure surfaces effective to move said valve in opposite directions, a port overrun by said hammer for conducting actuating fluid from said cylinder to one of said pressure surfaces for moving said valve, means responsive to such movement for subjecting one of said pressure surfaces to live motive fiuid and another of said surfaces to suction.

19. A pneumatic hammer having in combination a cylinder, a hammer, a valve, means for moving` said valve in one direction by actuating fluid from said cylinder and for holding said valve when so moved by live motive fluid and suction.

20. A pneumatic hammer having in combination a cylinder, a hammer, a valve, means for moving said valve in one direction by actuating fluid from said cylinder and for holding said valve when so moved by live motive fluid and suction, and means for changing said suction to positive pressure for moving said valve 1n the opposite '(lirection.

21. A pneumatic hammer having in combination a cylinder, a hammer, a valve, means for conducting motive fluid and allowing it to act upon a pressure surface of said valve for shifting said valve, a port opened in response to movement of said valve for admitting motive fluid and allowing it to act upon said pressure surface after said valve is shifted, and a storage reservoir for the motive fluid supplied by said port, said reservoir being formed in said penumatic hammer and being connected to the source of motive fluid supply for said pneumatic hammer by conduit means comprising a restricted passage.

22. A pneumatic hammer having in combination a cylinder, a hammer, a valve,

^ a port overrun by said hammer for conducting actuating fluid from said cylinder and allowing it to act upon a pressure surface of said valve for shifting said valve, a storage reservoir formed in said pneumatic hammer having a restricted communication with the source of motive fluid supply for said pneumatic hammer, and means including a port opened in response to movement of saidvalve for conducting motive uid from said storage reservoir and allowing it to act to lock said valve after said valve shifts.

23. A pneumatic hammer having in combination a cylinder, a hammer, a controlling valve, said valve having a forwardly acting working pressure surface and a rearwardly acting working pressure surface, means for conducting actuating fluid from the cylinder and allowing it to act on one of said pressure surfaces of said valve for shifting said valve, means responsive to movement of said lvalve for admittingair to the same pressure surface for locking said valve when shifted, and means for creating sucl. ion on the other of said pressure surfaces when said valve has been shifted.

A pneumatic hammer havin,D bination a cylinder, a hammer, a controlling valve, said valve having a forwardly acting working pressure surface and a rearwardly acting working pressure surface, means for conducting actuating fluid from the cylinder and allowing it to act on one of said pressure surfaces of said valve for shifting said valve, means responsive to movement of said valve for admitting air to the same pressure surface for locking said valve when shifted, means for creating suction on the other of said pressure surfaces when said valve has been shifted, and means for subjecting said last named pressure surface to positive pressure for again shifting said valve.

25. A pneumatic hammer having in combination a. cylinder, a hammer and a controlling va'lve, said valve havinga forwardly acting working pressure surface and a rearwardly acting` working pressure surface, and means for subjecting one of said surfaces to pressure fluid at high pressure for shifting said valve and the other to suction for locking said valve when shifted and for subjecting the latter pressure surface to positive pressure for overcoming the pressure on the first acting surface for again shifting said valve.

26. A pneumatic hammer having in combination a cylinder, a hammer and a controlling valve, said valve having a forwardly acting working pressure surface and a rearwardly acting working pressure surface, means for subjecting one of said surfaces to pressure fluid at high pressure for shifting said valve and to pressure liuid at low pressure when shifted, means for subjecting the other of said surfaces to suction when said valve is so shifted and for subjecting the latter pressure surface to positive pressure for overcoming the effect of the pressure fluid at low pressure acting on said first acting surface when said valve is to be again shifted.

27. A pneumatic hammer having in combination a cylinder, a hammer and a controlling valve, said valve having two opposed working pressure surfaces, means for admitting air for acting on one of said surfaces and for simultaneously creating suction by ejector action on the other of said surfaces, and said means exhausting to the atmosphere by way of the bore of said cylinder both the air admitted tothe first mentioned surface and the air for creating said suction.

28. A pneumatic hammer having in como' in combinuf'ion u Cylinder, n hrunlnel and a con trolling' valve, said valve having opposed pressure Snrfuces, a port overrun hy Suid hannner for conducting; air from 1he bore of said evlinder to one of Suid surfaces for moving Suid vulve, menus for Supplying live nir to Suid surface when said vulve is so moved, means 'for subjectingv the other of Said surfaces (.o suction h v ejector action when Suid valve is so moved, and Suid hist 10 named lnezrns exhausting' to the atmosphere by Way o'l ihe bore of Said cylinder.

In fest'i1non3v whereof. I have signed my naine to Jthis specification.

ERNEST H. SHAFF.

Certiicate of Correction.

It is hereby `certified that in Letters Patent No. 1,579,404, granted April 6, 1926, upon the application of Ernest H. Shaft', of Grand Haven, Michigan, for an improvement in Fluid-Pressure Motors, an error appears in the printed specification requiring correction as follows: Page 3, line 55, claim 2, after the Word hammer insert the Words piston, said valve; and that the said Letters Patent should be read With this correction therein that the same may Conform to the record of the case in the Patent Oice.

Signed and sealed this 11th clay of May, A. D. 1926.

[SEAL] M. J. MOOR-E,

Acting @ammissione/1" of Patents. 

